[Tutor] lambda

[bob gailer]

On 3/19/2011 9:44 AM, Ajit Deshpande wrote:
> I am trying to figure out where lambda functions can be useful. Has 
> anyone used them in real world?
>
> From my reading so far, I hear people claim that lambda can be a 
> useful replacement for small functions. Most examples  didn't make 
> much sense to me. Why would anyone use a one liner anonymous function, 
> if you never plan to use it elsewhere? You would then be implementing 
> the logic directly in the line, isn't it?. Functions are useful if 
> they plan to get called multiple times within your code.
>
> For example:
>
> add_one = lambda x: x + 1
>
> In real world, why would I use a lambda for this. I would simply do:
>
> add_one = x + 1
>
> Can you provide some useful use cases for lambda functions?

One is the list sort method.

someList.sort([cmp[, key[, reverse]]])

/"cmp/ specifies a custom comparison function of two arguments (list 
items) which should return a negative, zero or positive number depending 
on whether the first argument is considered smaller than, equal to, or 
larger than the second argument: cmp=lambda x,y: cmp(x.lower(), y.lower())."

-- 
Bob Gailer
919-636-4239
Chapel Hill NC

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/tutor/attachments/20110319/2b116e4f/attachment-0001.html>